BOSCH Turbo step drill Bits deliver extreme performance in metal in both high- and low-speed mode. The bits provide faster cutting, with 2x cutting edges for increased drilling speed. The high-speed design, Sharp cutting edges, and the premium heat management deliver enhanced bit life As well as premium hole quality. The two optimized cutting edges on the bit steps provide clean holes and up to 2x more holes per battery charge. They are made with a balanced double flute that helps to eliminate chatter and vibration. There is a wide range of hole sizes featured in this set. These bits are ideal for electrical, plumbing and HVAC contractors. They are made for electrical knockouts, running conduit, faucet installations and more, in materials up to 1/8 in. The bits work in materials such as sheet metal, ducts, steel, copper, brass, aluminum, plastic, vinyl siding, plasterboard, PVC, stainless steel and cast iron.